


The guy of Steel

by everybodyknowsme



Series: Some Problems were not created for certain people [1]
Category: Supergirl (TV 2015), ワンパンマン | One-Punch Man
Genre: Crossover
Language: English
Status: Completed
Published: 2018-10-25
Updated: 2019-03-14
Packaged: 2019-08-07 14:06:56
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,202
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16409885
Author URL: https://archiveofourown.org/users/everybodyknowsme/pseuds/everybodyknowsme
Summary: The crossover, that's long overdue.





	1. Showing up

Peter Johnson was just an ordinary cop. He had finished high school and college with not to bad, but also not great grades and then had gone to the police academy, where he again graduated, not bad but not good either. He lived and worked in National City. It sure got stressful, with all the aliens and whatnot, but he himself had never been involved in anything overly dangerous (except the daxamite invasion of course).  
So when an alien pocket thief ran towards his car, jumped in the back and screamed at him to drive, he knew he was going to be in over his head. He sat down in the driver seat and wanted to question his passenger, when more and more people came fleeing in his direction.  
Then he saw, what they were running from: tow creatures, one definitely was a CADMUS-agent, robotic parts clearly visible, less subtle than Cyborg-Superman or Metallo, the other one, a bald man in a yellow overall, was likely from CADMUS as well. They strolled down the street, as if they were confused by the panic, speaking to each other.  
Peter Johnson hit the gas and blindly reached for the radio. It took him some time, but eventually he grabbed it and seconds later, he saw a familiar blue shape speeding towards the CADMUS-agents.

Kara was in a bad mood. Reign's appearance alone was enough, to stress her out. Add to that, that her allies were her ex, his wife and a Coluan. When she got the call of a possible CADMUS attack, she just wanted to get it over with, as fast as possible.  
She approached the scene and noticed something odd: They were not speaking English, but rather an Asian sounding language, definitely human. Their tone was nowhere near as serious, as the situation should allow and then she saw them. Two Asians, one obviously a cyborg, huge metal arms, the face unnaturally evenly colored. The other one had a pretty athletic build and was slightly shorter than his partner. Even though he had no obvious augmentations, he looked suspicious non the less: he looked young, but was bald. And more importantly he wore something, that could only be described as a superhero costume. A yellow overall, red boots and gloves and a white cape.  
She briefly considered the possibility of him being an alien, but quickly dismissed it.  
“Surrender now and I will not beat you!”  
Unsurprisingly they did not seem to understand. What surprised her, was the way they looked at her. They pointed at her crest, the way someone, that had never heard of either her nor her cousin would. Maybe they were from another universe. But then why did her hovering several feet above them not faze them at all? Instead they were talking to each other, like they were arguing whether they should ask for directions.  
She floated down grab the cyborg. He reacted, by transforming one of his arms into a weapon.  
Her eyes started glowing.  
He was fast. He jumped, thrusters at his legs and shoulders as well as his arm-guns firing, propelling himself away from her. She tried to follow him, but came only a few feet, before she was stopped. She felt something like a grip on one of her feet and before she could turn to see, what could have possibly grabbed her, she was yanked to the ground lying at the bald ones feet.  
Her ankle hurt. She placed her other foot forward and moved to punch him.  
He caught her fist with his open hand. His face showed neither concern nor arrogance, but boredom, like she was just a nuisance and not one of the strongest entities he could have ever encountered.  
Then he ran, or rather walked extremely fast. His speed easily held up to her own, but he moved his body as if he was just walking. She pursued him. She could not allow a creature that strong, to wreak havoc in the city. Over the radio she notified the DEO about the fugitive cyborg.

 

Lena had just switched on her newest invention. For all she knew Hank Henshaw, the cyborg not the martian, was still free. So she had worked on a device, that should reduce the trouble he could cause. It worked like a lamp for a moth. It sent out a strong signal, that would overwrite the navigational components in a cybernetic brain. So now, when a cyborg within reach of the device attempted to go anywhere, he would get lost and uncontrollably steer towards her. The only navigation that remained possible, would be towards or away from her.  
Then a cyborg landed on her balcony. One whose augmentations looked vastly different than anything CADMUS could use. He knocked on the glass door, obviously wanting to speak to her.  
She opened, if he wanted to attack her, two-inch thick glass would not stop him.  
“Ma'am, I'm afraid something in here seems to interfere with my internal systems”, he said in Japanese.  
“You are not the cyborg I, wanted to catch.” She apologized and switched the device of.  
“Thank you. But it seems my systems have suffered lasting damage. I can't seem to reach the Hero-Association. Could you give me directions to the closest branch?”  
“I'm afraid, I have never heard of a company by that name.” Lena was excited. This could only mean one thing: the was from an alternate universe.  
“Did you breach into this universe on your own?”  
“What?”  
“My working theory is, that you are from another universe. Someway you must have crossed a temporary gateway. I want to know, if you were alone.”  
“Ah, so that were the strange lights. I guess master Saitama was the one, that brought us here.”

Supergirl began to suspect, that her opponent had no idea, where he was going. It became fact, when he stopped at a tourist map, drawing his finger over it, trying to find the dot, that marked his position. As she was approaching him from behind, his finger was following a highway out of the city. Then he fled again, going the wrong way. He noticed his error and decided to work around it.  
He jumped, landing on a skyscraper. He oriented himself and then jumped towards the old DEO desert-base.  
The were nearly out of the city, when she got a call from Lena. She ignored it. Her phone notified her immediately of a text and the her sister came in over the radio: “Do not engage!”  
“What?”  
“Lena called in just now and demanded I tell you that. Now she's speaking to fast for me to understand. You should call her.”  
So she did.  
“Do not attack the baldy!”  
“I'm not. Why? How do you even know about him?”  
“Because I hacked his cyborg disciple. They are from an alternate universe.”  
“And I should not apprehend him why?”  
“Because he's on our side. And because he eats threats like Reign for breakfast.”  
“I'll have you know, that I'm officially the strongest hero on two earths!”  
“I just saw him defeated a sea-monster in a 1/200 second and right now I'm watching him stopping an alien invasion single-handedly.”  
“You did that, too.”  
“I did not beat Rhea so hard into her ship, that it crashed.”  
“You're joking.”  
“I'll make a copy. Now, I assume, you don't speak Japanese.”

Thus the situation was resolved without a fight and when Kara saw Genos' recording of Saitama beating a monster to bits, that had just taken in enough damage do destroy a nuclear shelter, in the blink of an eye, she was glad for that.  
“So when the Flash came here, he could return, by running fast enough?”, Lena summarized.  
“Yes, but now we use these”, Supergirl held up the interdimensional extrapolator.  
“By now we've probably missed the farmers market in F-City”, Saitama sighted.

“Kara, do you want to join, to pay Morgan a visit?” Lena held up a pamphlet to an event neither of them was invited to.  
“I'd follow you everywhere! But why do you want to go there?”  
“Because I will not stand by, and let my mother kill him. And don't bother calling Supergirl. I already made measures to ensure our safety.”

When the attack-drones showed up, Lillian was surprised, to see a cyborg incinerating them. “You don't belong to CADMUS! Who made you?”  
“You want to hear my story? So be it...”  
After one minute of talking Lillian decided, that the identity of the scientist, that had constructed a cyborg without her knowledge, wasn't worth the trouble of listening any longer and she attacked.

Meanwhile Lena handed both Edge and Kara a glass of champagne and grinned:” I hope you brought a camera.”  
“He is one of the visitors, my sister told me about!”  
“Yes. And since they are both pretty much broke, even though one of them has world-ending strength, guess who got herself two new bodyguards for the week?”  
“I only see one.”  
“Yeah well, you see. I only ordered only him here. I wanted to keep the other one as a secret weapon, when I inevitably get abducted.”  
“Not much of a secret weapon, now that you told me”, Edge seethed.  
“You couldn't effectively prepare for Supergirl. I'm good.”

Of course Lena was abducted by Cyborg-Superman.  
“Why?”, She asked her captor.  
“What?”  
“Why did you abduct me? Do you need me to open another one of Lex' caches for you?”  
“Up until now, you and Supergirl were being protected by your mother. Now that your secret weapon turned her face into ash, it is time, to work effectively.”  
“I told her, she should wear a helmet, if she wasn't going to surrender. So what is your plan? Hold me hostage and hope Supergirl walks into your obvious trap?”  
“A plan does not need to be elaborate, if it works.”  
He switched a monitor on and it displayed the life-footage of the entrance-area of the bunker they were in. He left and could moments later be seen on the monitor.  
The bunker-door opened. It didn't slide sideways into the walls, like it was supposed to, but instead the steel-plates were folded upwards, like a carpet. Against the daylight the silhouette of a caped superhero could be seen. A male superhero. A hailstorm of kryptonite and lead flew towards him.  
After a few seconds of that having no effect, they realized that, in front them were neither Supergirl nor -man. The Cyborg attacked.  
The Cyborg was destroyed.

Saitama joined Supergirl to apprehend the suspected world-killer. Everyone was surprised, when the woman in question was peacefully listening to music. Alex didn't handle the surprise well and suddenly the suspect was screaming. The caped baldy held his hands over his ears and turned wide-eyed to his allies, who were in obvious pain.  
He was in a conundrum: he could stop the screaming, by hitting the woman, but that would require him, to take his hands of his ears.  
He walked up to her and told her to stop. The surprise over his action caused her to stop, so he wasted no time and slapped her KO.

At the DEO Julia Freeman woke up confused in a small cell, on the other side of one glass-wall were Supergirl, a dark-skinned man in black clothes, a red haired woman in similar attire, and a bald man wearing, what seemed to be a carnival costume, who had his back turned to her.


	2. Conclusion

**Notes for the Chapter:**

> Unless there is actual demand for more, I'll end this here.

At the DEO Julia Freeman woke up confused in a small cell, on the other side of one glass-wall were Supergirl, a dark-skinned man in black clothes, a red haired woman in similar attire, and a bald man wearing, what seemed to be a carnival costume, who had his back turned to her.  
“Where am I?”  
“Where you belong!”, the red-head shouted. “Alex!”, Supergirl stopped her outburst.  
Supergirl stared at Julia for a few seconds.  
“That is not the same woman, that attacked us.”  
“What?”, asked Alex and Julia at the same time.  
“When Saitama knocked her out, the shock-wave destroyed the windows. The woman in this cell is human. That hit would have left nothing of her body.”  
“So she can turn into a world-killer and back?”  
“I don't think Julia has much of a choice in that regard.” Supergirl went to open the cell.  
She was stopped by the black man: “I believe you, but until we know for sure, I will not risk the safety of the city. One world-killer is bad enough. Two working together would be disastrous.”  
“Could please someone explain to me, where I am, or why I am here?”  
“Do you know about Reign?”, Alex asked.  
Julia became visibly more afraid: “Only what's on the news. She's some kind of crazy Kryptonian.”  
„We believe, that she is not working alone. A trace lead us to your apartment. Do you still remember that?”, Supergirl said, trying to be as calming as possible.  
“No? I remember listening to music, then I walk up in here.”  
“I am not entirely sure, what happened in your apartment. When we came there, there was a woman, that I believe was you, listening to music. The woman noticed us and after a period of shock and confusion, she started to scream so hard it caused me physical pain. Literally. Do you happen to be a metal-human?”  
“No! I'm just a normal woman!”  
“Bullshit! You tried to kill Supergirl. If it hadn't been for Saitama here, you would've blown out all our eardrums.”  
“What she is trying to say is, that thanks to some help, we were able to apprehend the suspect and we put her in this cell. This is, why Alex believes, that you are dangerous.”  
“But I'm not dangerous! I'm just a normal human!”  
“How can we test this? If your theory is correct, she could be an innocent human right now, but turn into a dangerous Kryptonian at a moments notice.”  
“Maybe Lena can come up with something, that can prevent the transformation.”

“I can't help you.”  
“There has to be something, you can do!”  
“I didn't phrase that properly. I can't see anything, that would need to be done. First I used my alien-quick-test. It was negative. Then I took a blood-sample. Her cells appeared to be completely human, down to the DNA. So I used a micro-robot, to observe her cells, while they were still within her body. Again, definitely human. Then I had a thought: back when I was still working on my second PhD. I tried implementing mutation-chains into a genome, but I gave up, when my fruit-flies kept getting cancer.  
Well, with generations of using gen-technology for procreation it's not unreasonable, that Kryptonians figured out to do it. It makes sense. The world-killer comes to a world, becomes a member of the species for some time and then, they could turn Kryptonian as needed. So put a sample in a sequencer and sure enough,” she put up a screen, “in this inactive segment is a rupture. A part was recently removed.”  
Supergirl stared at the screen incredulously. All she could see was a graphical representation of a human genome.  
“How can you tell, something is missing?”  
“This sequence”, Alex pointed at a the screen, “would cause the cell to produce a highly destructive enzyme. If it had been active like this at any point in the past Ms. Freeman would have suffered severe internal bleeding. Can you tell, what causes this segment to become active?”  
Lena pressed a few buttons, and a series of chemical compounds was displayed, which she thankfully surmised in three words: “fight-or-flight.”  
“So unless we dragged the wrong body here, she somehow must have lost her world-killer-DNA between attacking us and waking up in our cell.”  
“Who knows, maybe Saitama beat the world-killer out of her.”  
“Supergirl, I know you were joking, but that's actually my only explanation.”  
“What?!”  
“Firstly, it wouldn't have been the first time, he's done something like that. He once punched a terrorist so hard, he became an upstanding citizen. Secondly, it's the only way, I can explain this. The sequence, that triggered the transformation was of Kryptonian make. It is not unreasonable to assume, that it would have a different structure, than the human DNA surrounding it, so an impulse of just the right frequency, could rip it out, without tearing the entire chromosome to pieces. CISPR or similar methods couldn't act this fast, and would be hard to apply to someone you keep a close eye on.  
The most pressing matter right now, is to fix this.”  
“Fix this?”  
“Yes? It's a miracle, that she didn't already die!”  
“Oh, you mean, give her proper human DNA! Yes, we should definitely get to this as quickly as possible. And we should let Julia out of her cell and tell her, she's no longer a suspect.”  
Supergirl ran off.

“So what do we do now?”, Alex asked into the round.  
Lena had only taken minutes, to alter Julia's DNA, so she was no longer in any danger.  
They had given Julia a panic-button, in case Reign tried to recruit her or she had inexplicable black-outs and released her.  
“We need to draw Reign out. We have a way of securely incapacitating her, without killing her. Even more, we can rehabilitate her; no need for some absurd prison, she would inevitably be busted out of. Are we all on the same page so far?”  
Everybody murmured in agreement.  
“Then I'll be the bait.”  
“Lena, no. that's to dangerous. I'll do it...”  
Lena pressed a finger on Supergirl's lips to stop her.  
“You know fully well, that you don't work as bait. Remember, what caused her last attack? Edge. If I pretend to go full Luthor, I will force her to react.”  
“No you'll just ruin your reputation. It is likely, that Reign is someone, that has a good opinion of you. She will likely see through it. However, there is something different, you could do”, J'onn reasoned.  
“Announce, what happened here today. Leave out Saitama's role. Just say, that you rendered a world-killer harmless. Talk, as if being a world-killer was nothing more than a genetic disease, that you could cure, and that people should seek treatment.”  
“I like that idea. I can make a charity-event out of this. Worst-case some people that can't normally afford to, get to see a doctor. What symptoms does being a world-killer have?”  
“Don't take it to lightly! There were supposed to be three world-killers, that means one is still unaccounted for.”  
“Pestilence! She might not be at full strength yet, but if she showed up in a large crowd, she could cause a disaster none the less.”  
“On this table are one Kryptonian, two experts of xenobiology, two geniuses, three if you count the Coluan with the 12th-level intellect, three people from the future and a cyborg from another universe! There has to be a way for us to scan for Kryptonians!”

J'onn's plan worked flawlessly. Genos was able to identify one of the volunteer-doctors as Kryptonian, who then grew long fingernails and tried to scratch Saitama.  
Reign tried to help Pestilence and was defeated as well.

**Author's Note:**

> Should I make more?


End file.
